Greetings to all. I could use some help on how this phrase might best be
translated ("because"?, "whereupon?") and therefore how it affects the
relation of the statements "death passed to all men" and "all sinned".

Thanks to all who are sharing your wealth of knowledge about the language
with those of us who are just getting started in NT Greek study. I'm doing
independent study in Mounce's grammar and enjoying it thoroughly. I highly
recommend it to anyone who wants to get started in learning the language.
"Greek to Me" has also been useful. Both of these have been recommended by
people on the list.